FACScans of changes in the epitopes in MSCs with expansion in culture. (A) Viable passage 1/donor 4 MSCs plated at 100 cells/cm² and incubated for 5, 6, 7, 8, or 9 days. Cells were lifted with trypsin/EDTA. (B) Data obtained with MSCs from 5 donors under conditions as in panel A. Values expressed either as mean fluorescence intensity (X-means) or percent positive cells. (C) X-mean values from panel B normalized to values for day 5. (D) FACScan from passage 1/donor 1 MSCs incubated as in panel A and assayed for STRO-1 and GD2. (E) X-means values from passage 1/donor 1 and donor 7 MSCs.